Varietal Effects on Winter Wheat Competitiveness in the Steppe Region of Ukraine

Winter wheat competitive ability against weeds in agrophytocenoses is determined, in part, by varietal characteristics, with implications for the grain yield of this globally important crop. Field experiments conducted in 2021–2023 were aimed at evaluating the competitive ability of the newest winter wheat cultivar of Ukrainian selection (Tsarychanka, Koshova, Oleksiyvka, Hratsiya Myronivska, Vezha Myronivska, Estafeta Myronivska) in the Steppe arid conditions. Weed abundance and pressure were determined by the dominant species Sinapis arvensis, Fumaria officinalis, Raphanus raphanistrum, and Thlaspi arvense, and varied depending on the crop development phase, maturity group of cultivars, and weather conditions. Early- maturing wheat cultivar displayed the highest biometric and structural parameters, such as plant height, leaf surface area, spike length, grain number per spike, and 1000 kernel weight, and were also characterized by the lowest weed air-dry mass in crops. Grain yield varied depending on the growing season conditions, reaching the highest average for all maturity groups in 2022 (7.12 t/ha), which was the highest for early-maturing cultivar in all years of research (6.31 t/ha). Thus, early-maturing cultivar excelled in terms of resistance to weed competition, adaptation to adverse climate conditions, and productivity, and were determined to be the most competitive among the newest cultivar of winter wheat created by Ukrainian breeders.